Balance Board: get sum value

[brononius]

I'm trying to rebuild the balance board to a digital garbage scale.
At the end, I would like to add some GPIO buttons, and when pressed, the weight should be logged.

With xwiishow, I'm nicely connected, and getting the values of the presuure. So connectivity is working.
I was wondering if I could only get the sum value somehow.

If I understand it correctly, the swiimote is more for GUI? Since it's a RP zero, and now screen will be attached, I'm looking for a CLI solution.